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Does weight loss reduce risk of early mortality?

The current recommendations from major health organizations stipulate that if an individual has a BMI in the obese range (>30 kg/m2), they should be counseled to lose at least 5-10% of their body weight. This advice appears to make some sense given that increasing body weight is generally associated with heightened risk of various diseases, and that reduction of body weight usually improves levels of risk factors for disease (e.g blood pressure, triglycerides, etc). However, the literature has been much more complicated in terms of the effect of weight loss on risk of early mortality.

Adding to that literature is a study by Ingram and Mussolino published in The International Journal of Obesity. In essence this study showed that weight loss of 15% or more was associated with an increased risk of death from all causes among overweight men and among overweight and obese women.

In the study, a sample of 6117 adults above 50 years of age from the National Health and Nutrition Examination Survey (2888 men and 3229 women) were followed from 1988/94 to 2000.

Quite simply, the authors divided the sample into 3 categories of weight loss (<5%, 5-15%, and >15%) and evaluated the prospective risk of mortality depending on the degree of weight loss, with separate analyses in each gender and even within different BMI categories (normal weight, overweight, and obese).

While that may sound straightforward, the way they ascertained the degree of weight loss is quite a bit more convoluted. First they asked the subjects at baseline: ‘Up to the present time, what is the most you have ever weighed? (FEMALES): Do not include any times when you were pregnant.’

During the follow-up time, there were 1602 deaths (835 men and 767 women). Interestingly, in contrast to persons with little or no weight loss (<5%, reference category), there was greater risk of early all-cause mortality among those who lost >15% of their maximum body weight, a finding which was statistically significant in overweight men, and in women of all weight categories (normal, overweight, and obese).

While these results may shock some of our readers, similar findings have been reported in numerous other studies. However, many such studies are confounded by various issues making the interpretation of their results rather difficult.

The major limitation to studies ascertaining the relationship between weight loss and mortality risk is delineating intentional (dieting, exercise, etc.) weight loss from unintentional weight loss (loss of body weight due to underlying disease, such as cancer). However, even studies that did separate between intentional and unintentional weight loss have shown conflicting results, suggesting that despite having positive effects on various indicators of health, weight loss may have a negative impact on longevity. Of course, even among those individuals who intentionally lose weight – the methods of doing so can vary widely, with some undertaking dangerous fad diets, extreme exercise or a regular regimen of random and often dangerous diet pills.

In this current study, all analyses were adjusted for age, race-ethnicity (white, black, Mexican-American), cigarette smoking status (current, former, and never), and history of health conditions related to excess weight and/or to weight loss. To try and control for unintentional weight loss, in addition to controlling for pre-existing health conditions statistically, respondents who died within 3 years of the baseline examination were also excluded.

Despite the new addition to the literature, the issue of weight loss and mortality is far from sorted out. The concern is always that our increasingly obese population will see such findings as a reason to discontinue healthy lifestyle behaviors, or as a reason to maintain their currently poor lifestyle.

It is key to remember that a healthy lifestyle has positive health effects regardless of what happens to one’s body weight.

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8 comments

This is really a great article! I think many factors involve in losing weight and the most important one is the diet or the plan. many people exercice every day without seeing any results because they are not steady and don’t stick to one diet.Also finding the right diet is a problem in it self and this is where most of the people stuck! i can suggest the half day diet, it’s an awesome diet plan, checkout this great review and you’ll be amazed! igrop.com/2016/02/the-half-day-diet-plan-review/ . I shared your article though 😀

Weight “loss” does not exist. We’re talking about fat people, here, not “normal” weight people who go up and down ten or fifteen pounds over and over. There is no such thing as a form of weight “loss” that permanently changes “obese” people into “normal” people.

You’re also a fucking spammer diet pusher who is likely doomed to rot in hell. Have a nice day.

As a biologist, I find the distinction between “intentional” and “unintentional” weight loss to be absurd. Do our cells and organs somehow check with the brain to make sure their relative starvation is purposeful before deciding whether to fail or not?
Regarding “unintentional” weight loss, there are many clinical studies done on this critical medical symptom. Epidemiolgists for some reason ignore the literature on spontaneous weight loss in patients. The most common reason is a gastrointestinal issue, and the weight is regained once the issue is resolved. The next most common reason is a psychiatric issue such as depression. Again, the weight loss is usually temporary. Cancer is not in fact a major cause of weight loss in medical patient populations. Cancer causes weight loss only in the later stages when tumors grow large and impinge on body structures or release toxic substances into the blood. The idea that the average person losing weight in the population does so because of the progression of a fatal disease is simply false.

Happy to see this discussion. It is very rare for people to think critically about the conventional wisdom.

The fact that almost every person regains weight except those who develop eating disorders says to me that weight regain is simply our body healing. Our perspective that weight loss is good is a recent and odd belief relative to most of human history.

Just one beef: “The concern is always that our increasingly obese population will see such findings as a reason to discontinue healthy lifestyle behaviors, or as a reason to maintain their currently poor lifestyle.” I am not sure if it was meant this way but to imply that body size is evidence of a “healthy” or “poor” lifestyle is highly problematic. We get on with supporting health and well being for all when we stop harassing people about whatever body feature is today’s scapegoat, and instead remove the environmental barriers to being able to easily practice loving care of our amazing bodies.

I agree Deb. They should stop the moralizing. How about the concerns over a weight obsessed lifestyle that eclipses every other aspect of existence? I don’t know too many obese people who are blithely eating Twinkie after Twinkie, oblivious to the health warnings. I do know people who have ruined body, mind and soul in a single minded pursuit of an unrealistic ideal. Quality of life is just as important as quantity. Amazes me how little they know about the psyches of fat people!